org.apache.hadoop.service.launcher.AbstractLaunchableService Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.service.launcher;
import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.service.AbstractService;
/**
* Subclass of {@link AbstractService} that provides basic implementations
* of the {@link LaunchableService} methods.
*/
@InterfaceAudience.Public
@InterfaceStability.Evolving
public abstract class AbstractLaunchableService extends AbstractService
implements LaunchableService {
private static final Logger LOG =
LoggerFactory.getLogger(AbstractLaunchableService.class);
/**
* Construct an instance with the given name.
*/
protected AbstractLaunchableService(String name) {
super(name);
}
/**
* {@inheritDoc}
*
* The base implementation logs all arguments at the debug level,
* then returns the passed in config unchanged.
*/
@Override
public Configuration bindArgs(Configuration config, List args) throws
Exception {
if (LOG.isDebugEnabled()) {
LOG.debug("Service {} passed in {} arguments:", getName(), args.size());
for (String arg : args) {
LOG.debug(arg);
}
}
return config;
}
/**
* {@inheritDoc}
*
* The action is to signal success by returning the exit code 0.
*/
@Override
public int execute() throws Exception {
return LauncherExitCodes.EXIT_SUCCESS;
}
}